Shortwave diathermy has been used over the last thirty years to stimulate tissue healing, especially in cases where conventional therapy is ineffective. Low frequency, medium power pulsed electromagnetic therapy (PEMT) devices have been used for example to accelerate fracture healing in refractory cases. Higher frequency PEMT devices have been used to accelerate inter alia wound healing. Conventional PEMT treatment regimens generally require mains operated power supplies. More recently battery powered devices have been used. However, irrespective of the power supply used in such devices electromagnetic pulse generation occurs at a site remote from the treatment site. In the case of a battery operated device the oscillator circuit is housed in the battery `box`. Such an arrangement has the disadvantages of high electrical losses, instability of resonating frequency and a limitation to a relatively narrow frequency range.
Direct current fields administered by implanted electrodes have been used in the treatment of breast and lung tumours in the last ten years. Experimental work has been reported indicating an inhibition of ascites tumour cell growth exposed to permanent magnets of high field strength (of the order of 4,000 gauss). However, there have been no reports of the use of pulsed high frequency electromagnetic fields in the inhibition of tumour growth.
It is an object of the present invention to provide an improved electromagnetic therapy (EMT) device which overcomes the aforementioned disadvantages of conventional electromagnetic therapy devices and which by virtue of its structure and mode of operation can be used in a wide variety of therapeutic applications.